Rhinovirus species A, C most likely to induce asthma exacerbation

HOUSTON — Rhinovirus species A and C were the species most significantly associated with asthma exacerbations among inner-city children, according to data presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

“In case-control studies of asthma, infections with rhinovirus-C (RV-C) and less so RV-A can cause acute wheezing, while RV-B is seldom associated with exacerbation,” study researcher Ann T. Esquivel, MD, of the University of Wisconsin, and colleagues wrote.

Ann T. Esquivel

To determine which rhinovirus species was the most strongly associated with asthma exacerbation, researchers analyzed 6,096 nasal mucus samples from 513 children aged 6 to 17 years who recently experienced asthma exacerbation and required parenteral steroids or hospitalization. Study participants were from low-income census tracts in eight U.S. cities. Samples were collected weekly during a 4-month period in the fall of 2012 and 2013.

“We know that low-income children tend to be disproportionally affected by asthma,” study researcher James E. Gern, MD, FAAAAI, of the University of Wisconsin, said in a press release. “Additionally, minorities tend to have worse asthma outcomes. It is important to increase our knowledge about asthma in these high-risk children as a first step towards improving asthma outcomes and quality of life.”

James E. Gern

There were 86 exacerbations during the study period. Viruses were detected in 66.7% of samples collected during an acute exacerbation, yielding 150 samples.

Rhinoviruses were observed in 56.7% of exacerbation samples and 36% of nonexacerbation samples (P < .001).

Rhinovirus species C was most commonly associated with asthma exacerbation (P < .001), followed by rhinovirus species A (P = .003). Rhinovirus species B was not significantly associated with exacerbation.

“The common cold certainly influenced the risk for asthma exacerbations in this outpatient study, and we found that rhinovirus species C and A were strongly associated with those asthmatic episodes,” Gern said in the release. “Interestingly, we also discovered that the group treated with omalizumab had a 20% reduction in viral detection. We think this may be from restored generation of an antiviral substance called interferon-alpha that helps to fight the common cold and other viruses.” – by Amanda Oldt

Reference:

Esquivel AT, et al. Abstract 528. Presented at: the American Academy of Allergy, Asthma & Immunology Annual Meeting; Feb. 20-24, 2015; Houston.

Disclosure: Infectious Diseases in Children could not confirm financial disclosures at the time of publication.